crypto: aead - Add chunk size

This patch adds a chunk size parameter to aead algorithms, just
like the chunk size for skcipher algorithms.

However, unlike skcipher we do not currently export this to AEAD
users.  It is only meant to be used by AEAD implementors for now.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/aead.c

@@ -346,9 +346,13 @@ static int aead_prepare_alg(struct aead_alg *alg)
 {
 	struct crypto_alg *base = &alg->base;
 
-	if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
+	if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
+	    PAGE_SIZE / 8)
 		return -EINVAL;
 
+	if (!alg->chunksize)
+		alg->chunksize = base->cra_blocksize;
+
 	base->cra_type = &crypto_aead_type;
 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 	base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;